Liberal Party elder Nick Greiner has launched a withering attack on the Abbott government's "abhorrent" practice of locking up children in immigration detention, saying Australia should join the rest of the civilised world and scrap the policy.

Mr Greiner described as "very sad" the government's disparaging response last week to an Australian Human Rights Commission report that revealed alarming rates of physical and sexual abuse against children in detention centres.

The strong criticism by the former NSW premier adds to a chorus of concern raised by other Liberal identities. NSW Premier Mike Baird said on Sunday children should be released from immigration detention and former prime minister Malcolm Fraser reportedly believes Prime Minister Tony Abbott handled the report badly.

The commission's report, The Forgotten Children, called for a public inquiry into children in mainland and offshore detention after findings of serious abuse.

Mr Abbott dismissed the call and described the report as a "transparent stitch-up". The commission's president, Gillian Triggs, said the report was fair-minded.

Mr Greiner, who was born in Hungary and migrated to Australia as a child, said the government's allegations of political bias served no purpose.

"It's typical of our inability to have a sensible debate on the substance of issues," he said.

"It's totally not surprising that the [commission] found the mandatory detention of children, especially unaccompanied children, has very serious deleterious effects on their mental and physical wellbeing."

Mr Greiner is also an adviser to the Andrew & Renata Kaldor Centre for International Refugee Law. He described as "awful" the fact that Australia was the only nation in the Organisation for Economic Co-operation and Development that indefinitely detained children in mandatory detention.

"The principle that Australia ... finds it necessary to be virtually the only civilised nation that does this, I think is just abhorrent," he said.

While the government's tough immigration policy had successfully stopped boat arrivals, Australia could "walk and chew gum … we now ought to look at the humanity of what we do", he said.

Last month Mr Baird called on Mr Abbott, a close friend, to "do more" to accept refugees. Asked on Sunday if children should be released from immigration detention, Mr Baird said "that's something I've supported for a long time".

The offices of Mr Abbott and Immigration Minister Peter Dutton did not respond to requests for comment.

ChilOut campaign co-ordinator Claire Hammerton, whose organisation lobbies to free children from detention centres, said the government's reaction to the report was "nothing short of shameful".